Stating with NSX-T Data Center 3.1.1, version 4 DHCP relay is supported on a VLAN-backed segment through the Service Interface. Only one DHCP v4 relay or service is supported on a segment.

To enable version 4 DHCP relay on a service interface:
  1. Create an isolated VLAN segment, with no DHCP related configurations such as DHCP-server, server-IP, ranges, or static bindings. See Add a Segment.
  2. Create a DHCP relay profile. See Add a DHCP Relay Profile .
  3. Create a service interface on the isolated segment, and configure DHCP type, ranges, options, static bindings, etc, on a Tier-0 or Tier-1 interface.
    1. Edit a Tier-0 or Tier-1 gateway. The Tier-0 gateway must be Active Standby HA mode.
    2. Select Interfaces > Set.
    3. Select Add Interface. Enter a Name.
    4. Select Service type.
    5. Select the VLAN segment from the drop-down Connected To (Segment) list.
    6. Enter the IP Address and subnet mask.
    7. Under DHCP relay, select the DHCP relay profile created in step 2, above.
    8. Click Save.
    9. Wait for the interface status to change to Success, and click Close.